Improvement in latches and locks



H. L. ARNOLD. LATCHES AND LOCK-S. o. 177, 11, Patented May 23, "may Beitknown that I, HORACE L. ARNOLD, of Grand Rapids, in the county of Kentand Latches, of which the following is a spe'cifica- V bineddoor-lockand knob=latch, to latch-opertionof bolts employed incombinationwith"the combi'nationof alever-tumbler, a spindlenormally-straight flatspring, which is deon latch-lever andtumbler, these latter being soarranged with relation to each other as to "enable them to properlyreceive and to be actuated by said spring, andto admit of the, springbeing readily, reversed side for side, when set or weakened from longuse inione position.

thestop which limits the movement of it. and the latch-lever.

UNITED STATES PATENT HORAGE Lpnn vo tnor QRAND RAPIDS, MICHIGAN.

IMPROVEMENT m LATVCHES IAND ,LQCKS.

' Specification forming" part of Letters Patent No. I 77,611, dated May23, 1876 application filed 1 July 10, 1875.

Toall whom it may-concern:

State of Michigan,-have invented certain new and useful Improvements inLocks 1 and tion: l

My said improvements relate .to a comating mechanism, and to a peculiarconstrucgated' lever-tumblers.

That portion of my invention which relates to a combined lock andknob-latch consists in hub,' having aV-shape'd notch, a latch-lever,provided with a stop for limiting its movement, and also with a V-shapedlug, springseats-on both, latch-lever and tumbler, and a flected byabutting endwise against its seats By my novel combination the springaffords a soi'tresistance to the key at the tumbler, a

light onthe strike, and which admits of the withdrawal of the latch byrocking the knobpenditure of practically the same degree of force at theknob, and at the same time the That portion of my invention whichrelates thecombination of a latch-lever having arms movement, and aV-shapcd lug on one of its dle-hub provided with a V-shaped notch forThatportion of my invention which relates theinitial point of contact ofthe key with said bolt, when the bolt is to be moved forward, isseparated "from the initial point of contact with the key when'the boltis to be moved in-w ward by aspace equal, or substantially equal,

to the distance which the bolttravels in being thrown forward or draw-ninward, whereby the bit of the key occupies nearlyv the same position atthe initial movement of the bolt in either direction, and also wherebyat the mo,- ment of said initial movements of the bolt the bit of thekey will hold the lever-tumbler in practically the same position,whether thebolt is to be thrown outward or withdrawn, in order that thewidth of the gating in the tumbler may be reduced to a minimum, and bebut a trifle wider than the thickness of the bolt'stump which passesthrough saidgating, thereby adding practically to the security of thelock.

To more particularly describe my improvements I will refer to theaccompanying drawin gs, representing locks embodying the severalfeatures of my invention.

. Figures 1 and 2 represent one of my looks with one side of the casedetached, showing the latch and lock bolts in the positions incident totheir use. portion of the lock with the tumbler detached. Fig. atrepresents the same as in Fig. 3, with the tumbler in working position.

The latch mechanism consists of the latchbolt A pivoted reversibly orotherwise (in a manner well-known) to the lower end of the three-armedlever B at a. Thelever B is pivoted 011 astud at b projecting from theside of the lock-case, and has aspringarm at c. Said lever has also acamarm at d,with which the spindlehub engages. Three armedlatchoperating levers have heretofore been. used. The novel feature ofmy invention in this connection is the two-faced cam-lug at e on abellcrank l'ever, which is provided with a stop for limiting itsmovement to the precise degree requisite for retiring the latch into thecase, in combination with a spindle-hub, as at O,

which is provided with a V-shaped cam-face,

so located with reference tothe two-faced FFIGE.

Fig. 3 represents the lower cam-lug e on lever B'that when thespindlehub is rocked one or the other of the sides of the /-shapedcam-face will engage with a corresponding face of the cam-lug, andthereby cause the lever B to vibrate and withdraw the latch-bolt. Itwill be seenthat the initial points of contact of the cam-faces on thespindle-hub with the faces of the lug are closely adjacent to eachother, and that as the hub is rocked in either direction the points ofcontact approach the lower point of the cam-lug,

and, therefore, although the two initial points of contact vary slightlyin their positions with relation to the fulcrum of the lever,thisvariation gradually lessens in degree up to the time the. latch-bolt isfully'drawn inward. The stop for the latch-lever, in this instance, isafforded by the interior surface of the upper portion of the rim of thelock-case, as at d. This arrangement of the parts secures a prompt, easymovement of the latch, with a slight movement of the spindle, and by theexpenditure of very nearly the same force, regardless of the directionin which the knob-spindle is turned; and at the same time, by reason ofthe stop which limits the movement of the latch-lever, the V- shapednotch and the V-shaped lug are always maintained in proper relations toeach other,

erating against the stud or lug farthest from the lever-fulcrum thanwhen operating againstthe lug nearest thereto. With my improved latch Iam unable to observe either that more force is requisite for withdrawingthe bolt by rocking the hub to the right than to the left hand, or thatthere is any difference in the extent of rocking movement in oppositedirections requisite for withdrawing the latch. A knob-latch soconstructed maybe made at low cost, and, by reason of the slightmovements requisite on part of hub and spindle, it has great durability.Moreover, by this construction of the cam lug and huh, I am enabled'touse a lever with a shorter arm than it is practicable to use when twowidely-separated cam lugs or studs are employed, and to that extent thelatch-case may be reduced in dimensions.

It will be obvious that the valve of the twofaced lug, and thespindle-hub with the V- shaped cam-face, will be substantially the samewhether they are employed with a threearmed lever, constructed as shown,or with a simple bell-crank lever. All knob-latches of this generalclass require a spring for holding nection with this portion of myimprovement.

The public demand a latch which shall, in trade-language, be heavy onthe hand and light on the strike, or, in other words, one in which theleverage shall be so distributed that the spring shall influence theknob strongly, and the catch only enough to insure its projection afterretraction. Therefore, it becomes practically an important point to makethe distance from the center of the threearmed lever to the point ofattachment to the latch-bolt exceed the distance from said center to thepoint at which the spindle-hub engages with the lever, as much as ispossible, in a medium-sized case.- This requirement is fully met by myarrangement, since I can reduce the length of the hub-arm as much as isdesirable. Commercially, this feature is of great importance, as aspring which is satis:

factory to the hand must act with a greatlydiminished force on the latchbolt or catch; otherwise, when the door is swung shut the violence ofthe blow required to force the catch into the lock-case speedilydestroys the strike, or loosens it on the door-post, or breaks thelock-case.

I am aware that in a certain so-called latchlock heretofore constructedthe retiring of the latch-bolt into the case is efiected by employing aspindle-hub of peculiar construction, and a lever pivoted at one end tothe case and arranged to engage by a hook-connection with the bolt, sothat when used as a lock-bolt a disconnection of bolt andlever may beeffected by' means of a key. In this latch-lock the spindle-hub isprovided with three camsfor I engaging with cam-surfaces on one edge ofthe lever, and is capable of complete rotation at all times, requiring,therefore, close atten-. tion at the knob to effect clearance of thebolt from its catch; and for this reason alatch so constructed, with orwithout the'addition allocking features heretofore employed therewith,is not suited for general use. In this instance I show the plain flatspring at D which is arranged to control not only the latch-bolt, butalso the lever-tumbler E, common to locks of this class.

Broadly considered, it is not new to combine with a tumbler and alatch-bolt lever a single spring arranged to control both; but so far as1 am aware, in all. such cases, the tumblers and latch-levers have beenso arranged, with reference to each other and to the remaining essentialparts of the lock, that said springs are required to be bent orspecially formed in order that they might perform this double service.

It is well known that the springs of a lock or latch are usually theparts of the mechanism which first become inoperative, and that whensuch springs break it is usually at the points where they have been bentso as to cause them to assume arbitrarily acertain form. It is also wellknown that such springs necessarily involve considerable bulk of metal,and are hardened or adjusted by hammering.

In my improved combined knob latch and look I have so arranged theseveral parts of the lock thata flat'spring may be combined withthelatch-lever and tumbler, and control both byexercising its abuttingforce at each ofits ends.

I attain economy in construction, 'as it involves only the cutting froma strip of spring metal a piece slightly longer than the straightlinedistance between suitable spring-seats on latch-lever and tumbler. Iattain durability in having a spring with no fixed bends, in having itfreely held in its seats, and in causing it to act from its ends, inthe. same manner, whether the latch-lever or the tumbler-lever bevibrated. I attain a soft easy resistance to the movement of latch andtumbler, because the spring, exercising its force endwise, may be madevery light, and yet be sufficiently powerful for the service required. Ialso attain in my lock, and with this spring, a capacity not attainablein any lock employing a specially-formed spring-heretofore known to me.i

It is obvious if a spring be specially formed or bent "so as to occupy acertain position and to perform a certain service, that if such springat any time naturally assumes the form it has when in service, it cannotbe reversed in position. On the contrary with the flat spring asemployed by me, if, through long use, it naturally assumes the curvedform incident to its position in service, and thereby becomesinoperative, it is only necessary, in order to renew its efficiency, totake it out, re-

verse it end for end, side for side, and cause What was before itsconvex side to become its concave side. I

It will be seen that the arrangement of ,the latch-lever and tumblerwith relation to the latch-hub and other portions of the lock is suchthat the flat spring may readily perform the double service. Inpractice, I prefer to slightly clip the corners of the spring at eachend in order to secure a good general bearing of the ends of the springswith their seats.

That portion of. my improvement which relates solely to looks isapplicable to those in which the boltis provided with a stump andcombined with a gated lever-tumbler. In all prior locks of this classwith which I am familiar, the tumbler occupies at the time of theinitial forward movement of the bolt a different position with relationto the key-bit than that occupied at the time of its initial backwardmovement. It is well known that at both of these initial movements ofthe bolt the gating in the tumbler should be in line with the stump onthe bolt in order to permit the entrance of the stump; and it will beseen that if the tumbler be not held by the key in the same position atthe time of [both initial movements of the bolt, the gating must be asmuch wider than is necessary for the passage of the stump as thevariation in the two positions occupied by the tumbler at the time ofsaid two initial movements of the bolt. It is also well known that inproportion as the gating is Wider than the thickness of the stump, theeasier the lock may be violated. One object of this portion ofmyinvention is to attain the reduction of the width of the gating in thelevertumbler to a minimum-that is to say, to have V the gating no widerthan is necessary to permit the clear passage of the stump. This Iaccomplish by a novel construction of the bolt at the key-notch, whichis clearly shown in Figs. 3 and 4. The well known symmetri-' calkey-notch or talon, which may be generally described as a square-sidednotch apwith which the key engages to throw the bolt forward is shown atg, and the backward point of contact at h, and it will be seen that theyare as far from each other in the longitudinal line of the bolt as thedistance traversed by the bolt in being locked or unlocked. In order tosecure to the bolt a full forward movement, the front side of the notchis extended downward and toward the rear of the lock-case, so that thebit of the key maintains its control over the bolt while moving overthis inclined surface. The notch is widened below on each side, as isusual, to afford full clearance of the key after the bolt has been fullymoved in either direction.

In Fig. the tumbler E is shown in its proper position, and it will beseen from the dotted and solid lines in this figure that whether thebolt is to be moved out or in that side of the notch which is to beengaged by the key Will always be one-half the thickness of the key-bitfrom the pointt' on the belly of the tumbler. Therefore, the key beingin contact with the tumbler at the same point at the time of bothinitial movements of the bolt, the gating is in position to allow theentrance of thestump 7c.

Another point gained by me with the talon or key-notch described is thesavingof one-- half the labor heretofore required for fitting the key.

It is obvious that since the tumbler is longitudinally stationary, andthe key-hole is also stationary, that unless the key-bit stands in onecertain position when the stump enters the gating, two points on thebelly of the tumbler must be fitted so that when the keybit is incontact with either point the gating shall be in the line of the travelof the stump.

In practice, with wing-keys the tumblers have, as .I believe, alwayshitherto been necessarily fitted at the two points referred to.

4 ileum-1 bring the'bit of the key to the same point, as

at 'i, on the tumbler, at the commencement of either the inward oroutward throw of the bolt, and by making this common point i fall} in aradius subtending the belly of the tumbler and tangential to thecircletraversed by the key-bit, I secure the liftand dwell requi- .sitefor the entrance of the stump into the narrow gating, and thus saveone-half the labor heretofore essentialin fitting keys-andi tumblers.

Having thus described myinven-tion. I claimas new, to be secured bytheseLetters Pat- I means of the stop which limits itsrocking movement,substantially as'describe'd.

cut-

1. In a combined knob latch and lock, a le-E yer-tumbler, aspindle-hubhav-ing a V -shapedi notch, and a latch-lever, provided withastopj for limiting its movement, and witha V-shaped' lug, incombination with spring-seats on latch lever and tumbler, and a normallystraight flat spring, which is deflected byabutting endwise against itsseat-s on latch-lever and tumbler, and is capable of being reversed sidefor side, substantially as described,whereby; the tuniblerofiers a softresistance to the key, the hub and latch lever are maintainedin} properrelations with each other, thelatch is made heavy on the hand and lighton the strike, and is withdrawn by the movement of the knob in eitherdirection with nearly an equal'degree of force on theknob,-and also"whereby'the spring may be'reversed in position aft-erit'is setorweakened, as set forth.

2. The combination of a latch-lever having unequal arms, providedwith-aiV-shaped 'lug on one of itsarms, and with a stop which limits itsmovement, with a latch, a spring actingon the leverfor throwing the-latch,

and a spindle-hub provided with a \I-shaped.

notch for engaging with the "l-shaped'lug on the latch-lever, andmaintained 'in proper working position, with relationlto said lug, by

'- 3. The combinatiomwith a..'gated lever' tumbler, ofa 'bolt providedwitha stump, and a key-notch which has a widthequalto the distancetraversed by the bolt, substantially as described, whereby at theinitial outward or inward movement of the bolt, the tumbler will occupythe sameposition-with relation to the line traveled by'the "bolt-stump,as set .forth.

HORACE L. ARNOLD.

Witnesses: v

WQH. V N Inn-WEN, Jr.,

H. VAN-AALDEREN.

